What is known about the LZB failure and the order that preceded the Urda crash

The sequence that is known of the shock of Urda (Toledo) on Wednesday 28 October comes from the statements of the Minister of Transport, Óscar Puente, and the audio of the control center of Adif in Atocha broadcast by the SER Chain, collected by Infobae. The judicial investigation and that of the Railway Accident Investigation Commission (CIAF) have not concluded.

The fall of the system. At 8:30 p.m., the LZB, the train control system on the Madrid-Sevilla line, stopped operating, and trains on the section stopped automatically. Puente spoke of a section of 63 kilometers and six trains affected, a figure that he said was not safe; Transport sources quoted by Europa Press spoke of 90 kilometers and El Independiente, of 65. According to Qué!, the failure was communication between three computers in the system.

At 8:31, the driver of the AVE 2080 the failure to the control center. At 8:36 he received this order, according to the transcription of the SER Chain: "Discontinue and re-connect the LZB and resume march under the BSL with normal operation." The Ministry of Transports says the regulation required to order "march to the eye", at a maximum of 40 km/h, according to El Independiente. According to Qué!, the maquinist of another train stopped corrected the center —«It cannot be a normal march; it must be a march in sight»—and the operator accepted the correction; it is not known if the AVE received that same correction.

The train ahead. At 8:41 the Iryo driver that he had lost transmission and was stopping at the Urda entry signal; at 8:48 he said: "The train is not allowing me to review the LZB system," according to the audio. There is no order to the AVE to stop or reduce speed, according to Infobae. Puente said both trains appeared "perfectly located" on the screens of the center, according to Qué!. Iryo sets the coup at 8:48; official information at 8:54.

According to Puente, quoted by Qué!, the AVE travelled about 25 kilometers in 15 to 17 minutes before the impact. Why he did not brake on time is not established: sector sources consulted by El Independiente believe that, by the track, the AVE did not find any other signal before the shock, so that the ASFA had no reason to brake; What! publishes that a red signal closed the entrance of the station. Experts from Adif consulted anonymously by Digital Freedom point to “an integral failure of the security system” and rule out that a human error is sufficient to explain it.

What is missing to know. Who authorized the order and with what information; why it was not corrected in the case of the AVE; what indicated the signaling between the resumption point and Urda; what speed the AVE circulated in each section, and why the LZB fell. the judge of Orgaz has decreed the secret of the actions and ordered the seizure of the black boxes of the two trains, according to Europa Press; the Civil Guard and the CIAF have questioned the operator of the control center, according to EFE.